Formation tester



Dec. 26, 1950 E, AHLGREN l 2,535,342

FORMATION TESTER Filed NOV.l 3, 1944 Patented Dec. 26, 1950 UNI-TEDSTATES PATENT y OFFICE FORMATION TESTER Erick L. Ahlgren, Houston, Tex.

Application November 3, 1944, Serial No. 561,744

l (c1. 16e-12) 3 Claims.

This invention relates to a formation tester.

' An object of the invention is to provide a formation tester of thecharacter described specially designed for use in connection with a gununit so that the -gun unit and tester may be lowered into a well and thecasing perforated so as to allow fluid from the surrounding formation toenter the casing and be collected by and entrapped in a chamber withinthe tester.

l Another object of the invention is to provide a formation tester ofthe character described embodying a novel type of valve assembly wherebythe sample chamber in the operating string of pipe will be normallyclosed at its lower end, with means for equalizing the pressure aboveand beneath the valve of said assembly so as to facilitate the movementof the valve to closed position after a sample of the formation has beentaken. Y

, The combined gun and tester are of such construction that the variousformations at diierent elevations may be tested without removing ,thetool from the well.

With the above and other objects in view the invention has particularrelation to certain novel features of construction, operation andarrangement of parts, an example of Which is given in this specificationand illustrated in the accompanying drawings, wherein:

` Figure l shows a vertical, sectional view of the combined gun andtester showing the packer collapsed and the sample chamber closed.

Figure 2 shows a vertical, sectional view showing the packer expandedand the sample chamber open to receive the sample.

Figure '5 shows a fragmentary, side elevation taken at right angles tothe view shown'in Figure 1; and

Figure 4 shows a cross sectionalview taken on the'line 4 4 of Figure l.

Referring now more particularly to the drawings wherein like numerals ofreference designate the same parts in each of the gures, the numeral Idesignates a tubular operating string of pipe which extends to theground surface and 4 into which the upper end of the nipple 5 is r;

tted. This nipple has an external annular flange 6 and a clamp nut 1 istted over the lower end of the nipple and screwed onto the lower end ofthe bar 3 and clamps the nipple in place. The nipple forms a connectionfor the well shooting gun 8 to the bar 3. This gun may be of anyconventional construction having a plurality of radial bores as 9, onlyone being shown, wherein is located the projectile l0. Behind eachprojectile there is an explosive charge II through which the electricalconductor I2 extends, there being an electrical conductor for eachprojectile charge. These conductors extend upwardly within a groove I3in the bar 3 and are connected at their upper ends to separate contactplates I4 located in the housing I5 into which the upper end of the baris formed. These contact plates are insulated from said bar and fromeach other. The charges may be red by suitable mechanism that may belowered through the operating string I such as disclosed in my copendingapplication, SerialNo. 549,074 iled August 11, 1944, now Patent No.2,396,768, granted March 19, 1946.

Around, and spaced outwardly from, the ba 3 there is a tubular packersupportv I6 providing a passage I6 through the packer and threaded ontothe upper end of the tubular support'l there is the tubular packerexpander I1 whose upper end is formed with an upwardly ared valve seatI8. Around the packer support there is a packer formed of rings I9 ofresilient material which are arranged alternately with respect to metalrings 20 and this packer is embraced by the upper and lower end plates2|, 22 which also surround the packer support I 6. The packer expanderI1 abuts the upper plate 2l and beneath the lower plate there is a jawexpander 23 slidably connected with the packer support and onto theupper end of which is screwed a ange nut 2l which abuts the lower plate22 and through which the packer support extends. The lower end of thepacker support I6 has an outwardly turned flange 25 which is beneath andengages with the inwardly turned ange of the nut 24 so as to interlockthe jaw expander 23 with the packer support I 6.

The expander 23 is hollow and is provided with the inlet ports 26 andits lower end has the downwardly tapering faces 21 on which the casingengaging jaws 28 are mounted to slide, said jaws having a dovetailedconnection with their corresponding faces. The jaw expander 23 also hasthe ducts 29 leading from beneath the expander into the interior passageI6' thereof. The jaw expander 23 has an internal tubular skirt 33 whichclosely surrounds the bar 3 and whose upper end has an internal annularange 3| which is engageable with an external upwardly facing shoulder 32on said bar 3 so as to limit the downward movement of the expander 23vrelativey to said bar. I

Surrounding the bar 3 beneath the jaw expander there is a tubular frame33 having the upper and lower inside rings 34 and 35 secured means onthe bar for supporting the jaw expander for limited downward movementrelative to the bar, casing engaging jaws on and surrounding the bar,means frictionally engageable with a surrounding casing releasablyconnecting the jaws to the bar in retracted position, said jaws beingengaged and expanded into engagement with the casing by said jawexpander upon release of said jaw connecting means and downward movementof the bar and jaw expander relative to the jaws, an annular packerassembly including an annular packer around the bar and supported by thejaw expander, an annular packer expander around the bar on the packerassembly and having an upwardly facing valve seat, said packer assemblyand expander having a passageway therethrough with anopening in eachexpander through which uid may flow from beneath upwardly through themaround the bar, a valve around, and slidable on, the bar above thepacker expander, means on the bar for supporting the valve in a lowerposition on the bar spaced above the packer expander seat, said barhaving a main duct with its lower end leading from an opening in theoutside surface on the bar below said tubular means and upper endopening into said tubular means connected into said string,`the lowerend of said main duct being closed by said valve when the valve is insaid lower position and said bar having a bypass duct Awhose endsterminate above and beneath said valve, respectively, when the valve isin said lower position, yieldable means surrounding said bar andengaging and urging the valve downwardly on the bar, the valve beingmovable downwardly by said bar into contact with the valve seat on saidpacker expander, to close the opening in said packer expander and expandthe packer assembly, said bar being movable further downwardly relativeto said valve to carry the lower end or' the main duct beneath the valveand into communication with said passageway and to carry the upper endof the by-pass duct within Said valve "to close the upper end of saidby-pass duct.

2. In a tester for wells, a bar, tubular means for connecting the upperend of the bar to a tubular operating string and communicating with saidstring, a tapered jaw expander around the bar and slidable relativethereto, means on the bar for supporting the jaw expander for limiteddownward movement relative to the bar, casing engaging jaws movablysupported on said jaw expander, means irictionaily engageable with asurrounding casing reieasably connecting the jaws to the bar inretracted position, said jaws being engaged and expanded into engagementwith the casing by said jaw expander upon downward movement or tne barand jaw expander relative to tne jaws, an annular packer assemblyincluding an annular pacser around tne bar and movaoly supportedthereon, an annular paexer expander around tne bar on the packerassembly and having an upwardly facing valve seat, said pacxer assemblyhaving a passageway therethrough through which lluld may Iiow frombeneath upwardly around trie bar, a valve around, and slidable on, thepar aoove the packer expander, llleans :or supporting the valve on tnebar in a position spaced aoove the pacxer expander and out or engagementwith said valve seat, said bar having a duct with its lower end leadingirom an opening in tne outside suriace oi' tile oar below said tubularmeans and wnose upper end opens into said tubular means, the lower endoi' said duct being closed by said valve when the valve is in saidspaced position, yieldable means surrounding said bar and engaging andurging the valve downwardly on the bar, the valve being movabledownwardly by said bar into contact with the valve seat on the packerexpander to close the passageway in said packer and to expand thepacker, said bar being movable further downwardly relative to said valveto carry the lower end of the duct beneath the valve and intocommunication with said passageway.

3. In a tester for wells, a tubular operating string adapted to belowered into a well, a bar, tubular means for connecting the upper endof the bar to said string and communicating therewith, a packer assemblyslidable o-n the bar and having a passageway therethrough through whichiluid may flow from beneath upwardly around said bar, said packerassembly comprising a tubular packer around the bar, and upper tubularpacker expander around the bar above the packer, and a lower tubularexpander around the bar beneath the packer and engageable by said barfor movement therewith, said lower expander having downwardly taperingfaces at its lower end, casing engaging jaws mounted on said lowerexpander for sliding movement relative tosaidtaperingfaces,resilientmeansslidablycarried on said bar below saidlower expander and frictionally engageable with said casing, link meansoperatively connecting said jaws and said resilient means, for movingsaid jaws outwardly along said tapering faces into engagement with asurrounding casing upon downward movement of said bar, releasable meansconnecting said resilient means with said bar for movement therewith toretain said jaws in retracted position, an upwardly facing valve seat onsaid upper packer expander, a valve around and slidable on the bar abovethe upper expander for movement into and out of engagement with saidvalve seat, means on the bar for supporting the valve out of engagementwith said valve seat, said bar having a main duct with its lower endleading from an opening in the outside surface of the bar below saidtubular means and whose upper end opens into said tubular meansconnected into said string, the lower end of said main duct being closedby said valve when said valve is supported by said supporting means outof engagement with said valve seat, and said bar having a by-pass ductwhose ends terminate above and beneath said valve, respectively, whenthe valve is out of engagement with the valve seat, yieldable meanssurrounding said bar and engaging and urging the valve downwardly on thebar, the valve being movable downwardly by said bar and said bar beingmovable further downwardly relative to said valve after the valveengages said seat to carry the lower end of the main duct beneath thevalve and into communication with said passageway and to carry the upperend of the by-pass duct within said valve to close the upper end of saidby-pass duct.

` ERICK L. AHLGREN.

REFERENCES CITED The following references are of record in the iile ofthis patent:

UNITED STATES PATENTS Number Name Date 2,029,491 Lane Feb. 4, 19362,330,509 McCullough Sept. 28, 1943

